Question 1:
An 86-year-old woman with a raised, reticular, pruritic rash on the left lateral shoulder of 2-3 months duration (Figure 1), estimated to have started after hospitalization for myocardial infarction. Medical history includes left shoulder osteoarthritis, untreated torn left rotator cuff, and left-sided breast carcinoma treated with lumpectomy 30 years prior. A punch biopsy of the area showed the following histopathology (Figure 2a-2c). The cytokeratin AE1/AE3 stain is also shown (Figure 3a, 3b).
Figure 1.
Figure 2a.
Figure 2b.
Figure 2c.
Figure 3a.
Figure 3b.
What is the most likely diagnosis?